To improve electromagnetic noise, power source higher harmonics, internal loss, waveform distortion, response, manufacture cost, etc., by providing a voltage generating means which is so constituted that the output voltage of, each power source is a specific multiple of a minimum output voltage, and a circuit switching means and a polarity switching means which are specific.

This controller consists of an AC power source 1, a transformer 2, a circuit switching operation part 3 which is constituted by connecting a rectifying circuit, a smoothing circuit, or a battery to each of six secondary coils of the transformer 2 and adjusts a composite output voltage E2 digitally and continuously by switching combinations of output voltages V1-V6 with switches 31-39, and 310-312, a polarity switching operation part 4 which converts a DC voltage into an AC voltage by inverting the polarity of the voltage E2, and a filter 5 for waveform shaping. Here, There are 64 DC connections of output voltages V1-V6 of a voltage generator group in binary notation. Therefore, when V2=2×V1, V3=4×V1... V6=32×V1, the composite voltage E2 can be adjusted digitally and continuously within a range of 0 to 63×V1.